The parish church of Sainte Eugénie de Saillagouse is mentioned in the act of consecration of the Seu d'Urgell in 839.

The current church was built in the Romanesque style, with a gear-tooth frieze on the south wall supported by sculpted modillions depicting human heads.

The building was extensively modified in the 18th century under Louis XV. The apse to the east was destroyed and replaced by the present doorway. The baroque altarpiece of the High Altar was added to the west. The side façades were pierced to add chapels, causing numerous leaks that have dilapidated the altarpieces and altars.

It was built during the reign of Alfonso II (1162-1196), King of Aragon and Count of Barcelona and Rousillon, who tirelessly pursued the crusade against the Spanish Moors to the south of Barcelona and Aragon.

He used the tribute he received from the Moors to build 300 churches, some of them in Cerdanya, and it is likely that the church in Saillagouse benefited from the tribute he received from the king, who spent his summers at his count's house in Hix.